The present invention relates to a device for locking a rotor blade of a wind turbine which comprises an adjustment system for the blade pitch angle of the rotor blade. The adjustment system has a drive which comprises a motor and a gearbox, wherein a gearbox input shaft bears an external toothing.
DE 100 31 472 C1, the entire contents of which is incorporated herein by reference, discloses a device for locking a shaft of a wind turbine driven by a rotor. For locking, a toothed disc is provided on the driven shaft, which is realized as a toothed disc. A locking element has a projection which interacts with the two teeth of the toothed disc.
DE 10 2004 017 323 A1, the entire contents of which is incorporated herein by reference, discloses a locking device for holding the rotor blade in an adjusted angular position essentially free of clearance. The locking device has a tensioning slider and a tensioning device, wherein the tensioning device is coupled to the rotor blade and the tensioning slider is arranged stationarily on the rotor hub. In a predetermined angular position in which the rotor blade is to be locked, the tensioning device and the tensioning slider engage one with another, and lock the rotor blade.
A hydraulically actuated blade pitch adjustment device is known from DE 31 10 263 C2, the entire contents of which is incorporated herein by reference. In this document each of the blade roots is provided with a groove in its perimeter. A device for locking in the feathered position is arranged adjacent to the blade perimeter and comprises a locking element, which is biased towards the blade root by a spring. The locking element is actuated hydraulically and interacts with the groove on the blade root.
EP 1 029 176 B1, the entire contents of which is incorporated herein by reference, discloses, a wind turbine in which an adjustment of the rotor blade position is performed by a lock that can be activated when the power supply of the drive breaks down. In its activated condition, this lock prevents the rotation of the rotor blades, yet it permits to turn the rotor blades into the feathered position.
For wind turbines different maintenance operations must sometimes be performed on the rotor hub. In order to protect the maintenance operators from injuries by rotating parts, it is often also provided to fix the blades in their position via the brake of the drive motors, however this has the disadvantage that there is no positive fixation of the position and that it is not possible to fix the blades in their position during maintenance works on the brake.
The present invention is based on the objective to provide a locking device for a rotor blade of a wind turbine, which allows a reliable and effective fixation of the rotor blade in any arbitrary position by simple means.